Modular belts have modules with leading and trailing eyes, and adjacent modules are positioned such that the leading and trailing eyes are intercalated. A hinge rod is introduced through the intercalated leading and trailing eyes to connect the modules to one another to form a belt. Such belts are typically looped between drive and idler sprockets or drums, and the modules have protrusions that engage the drive sprockets such that the belt can be continuously driven.
Problems exist with respect to maintaining such modular belts in a clean and sanitary condition. For example, in the food industry meat products are commonly conveyed from one work station to the next on a conveyor belt such as the one described above. However, there are spaces between the leading and trailing eyes and rods, and these spaces provide an ideal environment for mold and bacteria growth. In addition, regardless of how often the modular belt is washed, the spaces between the leading and trailing eyes and rods are not cleaned. A thorough washing can only be accomplished by disassembling the modular belt into its individual components and washing each component separately. Disassembly of the entire modular belt results in undesirable down time and decreased productivity. Thus, there is a need for a modular belt that overcomes the problems associated with such modular belts.
An example of an endless belt design is shown in U.S. Pub. No. 2004/0089519 to Pollak et al. (hereinafter Pollak et al.) that does not have any hinges. The belt described in Pollak et al. is made of homogenous or monolithic materials and made by an extrusion process. However, there are many problems associated with this belt design. The belt material must be flexible enough to allow the belt to bend around the drive and idling drums, which is not always the case with such belts. In addition, the surface of a belt made of such an elastic or monolithic material does not resist scratches, cuts and damage associated with mechanical cutting. In addition, in the food industry, the belt surface is oftentimes subjected to cutting and impacts and the monolithic belt cannot withstand such impacts and cutting. Another problem with such a monolithic belt is that the flexibility of the belt material required to bend around the idler and driving drums results in the belt having a high longitudinal flexibility as well, which is disadvantageous when the belt is under load. Another problem associated with such flexible belts is that there is a frictional load increase. For example, these belts are drawn over supports made of wood, steel plates or steel strips, and the frictional load caused by the belt can be in excess of the frictional load generated when modular plastic belts are drawn over the supports. This has the disadvantage of energy losses, decreased working life of the belt, and limiting the maximum load on the belt.
Thus, there is a need for a belt that is hingeless that does not increase friction or increase power requirements, that can withstand cutting and impact operations, that does not have increased longitudinal flexibility, and that is easy to thoroughly clean.